Photo Source: My Modern Met. France-based street artistMantra transforms multi-story buildings into gigantic butterfly specimen cases in a series of clever, trick-of-the-eye 3D murals. The enormous, hyper-realistic butterflies appear to be set within wooden-framed boxes, recessed into the side of each building. Long shadows and subtle details, which suggest a transparent glass surface, create a convincing level of depth that helps to enforce the head-turning optical illusions.